SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '970fa24cb1030a8c8959b65f775ffb327c90081185da819b4e926cd22ab41d71' 
  AND token = 'SxpWqm8Bq5G2JNCJqlFLuY664rmyepwhaq0KOmuXvo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}